The key to understanding this point is to know that the Old Testament law was given to the nation of Israel, not to Christians. Some of the laws were made so that the Israelites would know how to obey and please God (e.g., the Ten Commandments). Some of these were to show them how to worship God and how to pay for sin (the sacrificial system). Others were simply to make the Israelites different from other nations (the rules about food and clothing). None of the Old Testament laws apply to us today. When Jesus died on the cross, He put an end to the Old Testament law ( Romans 10:4 ; Galatians 3:23-25 ; Ephesians 2:15 ).
Instead of being under the Old Testament Law, we are under the law of Christ ( Galatians 6:2 ) that is “You shall love the Lord your God with all your heart, and with all your soul, and with all your mind. This is the first and great commandment. And the second is like it: You shall love your neighbor as yourself. On these two commandments hang all the Law and the Prophets” ( Matthew 22:37-40 ). If we do these two things, we will be fulfilling everything Christ wants us to do: “On these two commandments hang all the Law and the Prophets” ( Matthew 22:40 ). Now this does not mean that the Old Testament law is irrelevant today. Many of the commandments in the Old Testament law fall into the categories of “loving God” and “loving your neighbor.” The Old Testament law can be a good guide to knowing how to love God and knowing what loving your neighbor entails. At the same time, to say that the Old Testament law applies to Christians today is incorrect. The Old Testament law is a whole ( James 2:10 ). Either it applies in its entirety, or none of the law applies. If Christ fulfilled part of the law, such as the sacrificial system, then He fulfilled all of it.
“For this is the love of God, that we keep His commandments; and His commandments are not grievous” ( 1 John 5:3 ). The Ten Commandments were essentially a summary of the entire Old Testament law. However, nine of the Ten Commandments are repeated in the New Testament (all except the command to observe the Sabbath). Obviously, if we are loving God, we will not be worshiping other gods or worshiping idols. If we are loving our neighbors, we will not be murdering them, lying, committing adultery against them, or coveting what belongs to them. The purpose of the Old Testament law is to convince people of our inability to keep the law and to point to our need for Jesus Christ as Savior ( Romans 7:7-9 ; Galatians 3:24 ). God never intended the Old Testament law to be a universal law for all people and for all time. We are to love God and our neighbor. If we obey those two commandments faithfully, we will be fulfilling all that God requires of us.